Ensure you aren't missing any .rar files in the sequence.
The v1.17 update was a maintenance patch released by Ubisoft to address community-reported issues. Watch.Dogs.2.MULTi16.Update.v1.17.part4.rar
Watch_Dogs® 2 - Watch Dogs 2 – 1.17 Patch Notes – Bug Fix Patch - Steam News. Ensure you aren't missing any